package com.zds.servlet;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

@WebServlet("/Uploadfile")
public class UploadServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private static final String UPLOAD_DIRECTORY="upload";

    //上传配置
    private static final int MEMORY_THRESHOLD = 1024 * 1024 * 10;//10m
    private static final int MAX_FILE_SIZE = 1024 * 1024 * 50;//50m
    private static final int MAXREQUEST_SIZE = 1024 * 1024 * 50;
    /*
    * 上传数据及保存文件
    * */
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        if (!ServletFileUpload.isMultipartContent(req)){
            PrintWriter writer = resp.getWriter();
            writer.println("Error:表单必须包含enctype = multipart/form-data");
            writer.flush();
            return;
        }
        //配置上传参数
        DiskFileItemFactory factory  =  new DiskFileItemFactory();
        //内存临界值，超过后将产生临时文件并存储于临时目录中
        factory.setSizeThreshold(MEMORY_THRESHOLD);
        //设置临时存储目录
        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

        ServletFileUpload upload = new ServletFileUpload(factory);
        upload.setFileSizeMax(MAX_FILE_SIZE);
        upload.setSizeMax(MAXREQUEST_SIZE);
        upload.setHeaderEncoding("UTF-8");
        String uploadPath = getServletContext().getRealPath("/")+File.separator+UPLOAD_DIRECTORY;
        File uploadDir = new File(uploadPath);
        if (!uploadDir.exists()){
            uploadDir.mkdirs();
        }
        try {
            // 解析请求的内容提取文件数据
            @SuppressWarnings("unchecked")
            List<FileItem> formItems = upload.parseRequest(req);

            if (formItems != null && formItems.size() > 0) {
                // 迭代表单数据
                for (FileItem item : formItems) {
                    // 处理不在表单中的字段
                    if (!item.isFormField()) {
                        String fileName = new File(item.getName()).getName();
                        String filePath = uploadPath + File.separator + fileName;
                        File storeFile = new File(filePath);
                        // 在控制台输出文件的上传路径
                        System.out.println(filePath);
                        // 保存文件到硬盘
                        item.write(storeFile);
                        req.setAttribute("message",
                                "文件上传成功!");
                    }
                }
            }
        }catch (Exception e){
            req.setAttribute("message","错误信息："+e.getMessage());
        }
        getServletContext().getRequestDispatcher("/message.jsp").forward(req, resp);
    }
}
